EN Savory Selects Gastroenteric® Canned Feline Formula with salmon in Gravy Purina Pro Plan Veterinary Diets EN Gastroenteric Feline Formulas are energy-dense and support the unique nutritional needs of cats with GI conditions. Made with high-quality ingredients, these diets also support urinary health. The science behind our therapeutic diets represents a collaboration between Purina pet nutrition experts, researchers and veterinarians.